Critical Care 2010, Volume 14 Suppl 1 http://ccforum.com/supplements/14/S1 MEETING ABSTRACTS 30th International Symposium on Intensive Care and Emergency Medicine Brussels, Belgium, 9-12 March 2010 Published: 1 March 2010 P1 P2 Comparison of carbamylated versus recombinant erythropoietin Sodium 4-phenylbutylate protects against myocardial during spinal cord ischemia/reperfusion injury ischemia-reperfusion injury by reducing unfolded protein F Simon, A Scheuerle, A Soell, M Groeger, O McCook, P Radermacher, response-mediated apoptosis in mice M Georgieff , E Calzia, H Schelzig M Okajima1, M Takamura2, S Usui2, T Taniguchi1, S Kaneko2 Ulm University, Ulm, Germany 1Kanazawa University Hospital, Kanazawa, Japan; 2Kanazawa University Critical Care 2010, 14(Suppl 1):P1 (doi: 10.1186/cc8233) Graduate School of Medical Science, Kanazawa, Japan Critical Care 2010, 14(Suppl 1):P2 (doi: 10.1186/cc8234) Introduction We previously showed that erythropoietin (EPO) attenuates the morphological signs of spinal cord ischemia/reperfusion (I/R) injury Introduction Unfolded protein response (UPR)-mediated apoptosis plays a in swine [1] without, however, improving neurological function. The pivotal role in ischemia-reperfusion injury. Sodium 4-phenylbutyrate (PBA) clinical use of EPO has been cautioned most recently due to serious safety has been reported to act as a chemical chaperone inhibiting UPR-mediated concerns arising from an increased mortality in acute stroke patients apoptosis triggered by ischemia in various organs other than the heart. treated with EPO and simultaneously receiving systemic thrombolysis Therefore we investigated whether PBA reduces UPR-mediated apoptosis [2]. Carbamylated EPO (cEPO) is an EPO derivative without erythropoietic and protects against myocardial ischemia-reperfusion injury in mice. activity and devoid of the EPO side eff ects, but with apparently well Methods C57BL/6 mice were subjected to 30 minutes LAD ischemia maintained cytoprotective qualities [3]. We therefore tested the hypothesis followed by reperfusion. PBA (100 mg/kg) or PBS (control) was adminis- whether cEPO may be equally effi cient as EPO in reducing morphological trated intraperitoneally just before ischemia. Apoptosis, infarct size and as well as functional aortic occlusion-induced spinal cord I/R injury. tissue protein levels of Grp78 and caspase-12 (UPR-mediated apoptosis- Methods In a randomized and blinded trial pigs received either vehicle associated protein) were evaluated by TUNEL, TTC stain and western blot (control, n = 9), EPO or cEPO, respectively (n = 9 each; 5,000 IU/kg over analyses, respectively, at 48 hours after ischemia (n = 5 for each group). 30 minutes before and during the fi rst 4 hours of reperfusion). Animals Echocardiography was performed at 3 weeks after ischemia and the underwent 30 minutes of thoracic aortic balloon occlusion with catheters survival ratio was observed (n = 9 for each group). placed immediately downstream of the A. subclavia and upstream of the Results Compared with PBS, PBA reduced apoptotic cells (30.8 ± 0.2% vs aortic trifurcation. Spinal cord function was assessed by motor evoked 20.5 ± 0.5%, P <0.05) and infarct size (32.0 ± 3.8% vs 13.0 ± 2.1%, P <0.01) potentials (MEP as percentage of the amplitude before aortic occlusion) after ischemia-reperfusion. Grp78 and caspase-12 were increased in and lower limb refl exes (assessed as the subjective strength of response) mice with PBS, but PBA attenuated the increase in Grp78 (P <0.05) and for a period of 10 hours after reperfusion. Tissue damage was evaluated caspase-12 (P <0.05). PBA inhibited the deterioration of cardiac parameters using Nissl staining. including LVEDD (3.35 ± 0.08 mm vs 2.74 ± 0.11 mm, P <0.01), LVESD Results Both EPO-treated and cEPO-treated animals presented with (2.30 ± 0.08 mm vs 1.54 ± 0.12 mm, P <0.01), and %FS (31.3 ± 2.2% vs 39.4 ± attenuated spinal cord injury in the Nissl staining (median (quartile) 2.2%, P <0.05). All mice with PBA survived, but 33% animals with PBS died. percentage of damaged neurons in the thoracic segments: control 27 Conclusions PBA maintained cardiac function and improved survival (25,44), cEPO 8 (4,10), and EPO 5 (5,7), P <0.001 vs control group; in the ratio after myocardial ischemia-reperfusion by reducing UPR-mediated lumbar segments: control 26 (19,32), cEPO 7 (5,13), EPO 8 (5,10), P <0.001 apoptosis in mice. vs control group). However, while only cEPO treatment was associated References with recovery of the MEP amplitude to pre-occlusion values when 1. Qi X, et al.: Mol Pharmacol 2004, 66:899-908. compared with the control group (P <0.05), lower limb refl ex response 2. Vilatoba M, et al.: Surgery 2005, 138:342-351. was comparably restored stronger in both treatment groups (P <0.05 vs control). Conclusions In a clinically relevant porcine model mimicking aortic cross- clamping during vascular surgery repair of thoracic aortic aneurysm, cEPO protected spinal cord function and integrity as eff ective as EPO when applied at equipotent doses. Acknowledgements Supported by the Deutsche Forschungs gemein- schaft (SCHE 899/2-2). References 1. Crit Care Med 2008, 36:2143-2150. 2. Stroke 2009. [Epub ahead of print] 3. J Int Med 2008, 264:405-432. Figure 1 (abstract P2). Phenylbutyrate reduced the unfolded protein response. © 2010 BioMed Central Ltd © 2010 BioMed Central Ltd Critical Care 2010, Volume 14 Suppl 1 S2 http://ccforum.com/supplements/14/S1 P3 the animals mechanically ventilated while supported in a sling. Six sheep 8 Time-dependent eff ects of intravenous H2S during long-term, were administered intravenous E. coli (ATCC 25922) 1.0 x 10 orgs/kg over resuscitated porcine hemorrhagic shock 1 hour (septic sheep), fi ve received placebo (nonseptic sheep). For 24 hours, H Bracht1, F Simon1, B Hauser1, M Groeger1, A Soell1, O McCook1, animals were monitored and received sedation (midazolam + ketamine), M Georgieff 1, P Radermacher1, C Szabo2, E Calzia1 ventilation, fl uids and inotropes according to a protocol. Primary end-point 1Ulm University, Ulm, Germany; 2University of Texas Medical Branch, was noradrenaline (NA) dose to maintain mean arterial pressure (MAP) Galveston, TX, USA of 75 mmHg. Secondary end-points included haemodynamic variables, Critical Care 2010, 14(Suppl 1):P3 (doi: 10.1186/cc8235) respiratory, hepatic, and renal function, haematology, acid–base status and global, hind-limb, renal, hepatic and coronary oxygen extraction ratio (OER). Introduction In awake, spontaneously breathing mice, inhaling hydrogen Results Sheep were successfully instrumented, monitored and supported sulfi de (H2S) induced a hibernation-like metabolic state characterised by for 24 hours. Septic sheep required NA (mean dose 0.28 μg/kg/min vs 0.00, reduced energy expenditure and hypothermia [1], which protected against P <0.001), developed a higher cardiac index (6.6 l/m2 vs 4.3, P <0.05) and otherwise lethal hypoxia [2] and hemorrhage [3]. In contrast, other authors lower SVRI (769 dynes/m2 vs 1,804, P <0.05). At 24 hours, septic sheep had reported that inhibition of endogenous H2S synthesis attenuated post- renal impairment (creatinine 286 mmol/l vs 76, P <0.05; urea 12 mmol/l vs hemorrhage organ dysfunction [4,5]. All these data originate, however, 7, P <0.05), metabolic acidosis (pH 7.21 vs 7.39, P <0.05; lactate 10.9 mmol/l from unresuscitated models using a pre-treatment design. Therefore we vs 1.2, P <0.01; pCO2 32 vs 31, P = 0.63), coagulopathy (INR 5.9 vs 1.9, investigated the time-dependent eff ect of intravenous H2S in a clinically P <0.05; fi brinogen 0.9 g/l vs 2.7, P <0.05) but preserved respiratory and relevant, long-term model of porcine hemorrhage and resuscitation. hepatic function. Global OER was lower in septic sheep (0.16 vs 0.29, Methods After surgical instrumentation, pigs were subjected to 4 hours P <0.05) as was coronary OER (0.36 vs 0.68, P <0.05). OER did not change of hemorrhagic shock induced by removal of 40% of the calculated blood with sepsis in the kidney (0.09 vs 0.11, P = 0.52), liver (0.24 vs 0.31, P = 0.48) volume and thereafter by additional removal or retransfusion of blood boli and hind-limb (0.31 vs 0.42, P = 0.23). as needed to maintain MAP = 30 mmHg. Animals randomly received vehicle Conclusions We have developed a large animal model of septic shock (control, n = 14) or the intravenous H2S donor Na2S started 2 hours before that receives intensive care support and standardised management. This hemorrhage (pre-treatment, n = 11), at the beginning of blood removal model replicates much of the pathophysiology and management that (early post-treatment, n = 10) or at the beginning of resuscitation (late occurs in human septic shock. It allows a large range of physiological post-treatment, n = 10). In all groups the Na2S infusion was continued over parameters to be assessed when investigating new therapies for sepsis. the fi rst 10 hours of reperfusion. Resuscitation comprised retransfusion of shed blood, colloid volume expansion, and noradrenaline titrated to keep MAP at pre-shock levels. Systemic, renal and liver perfusion, O2 exchange, and organ function were assessed before and at the end of hemorrhage as well as at 10 and 22 hours of resuscitation. P5 Results Survival (71% in the control vs 100, 91, and 90% in the pre- Eff ects of temperature and H2S inhalation on glucose metabolism in treatment, early post-treatment and late post-treatment groups, respec- murine resuscitated septic shock tively) was signifi cantly improved in all treatment groups. The noradrenaline K Baumgart1, F Wagner1, V Hysa1, J Vogt1, U Wachter1, S Weber1, infusion rate required to maintain hemodynamic targets was signifi cantly M Georgieff 1, P Radermacher1, C Szabo2, E Calzia1 reduced in the early post-treatment group only, which coincided with a 1Ulm University, Ulm, Germany; 2University of Texas Medical Branch, progressive drop in core temperature and attenuated kidney dysfunction Galveston, TX, USA (blood creatinine levels, creatinine clearance) in these animals.